Laboratory diagnosis of norovirus.

Noroviruses are considered the most common cause of outbreaks of non-bacterial gastroenteritis worldwide, as well as being an important cause of sporadic gastroenteritis. Noroviruses were discovered by electron microscopy and this method played an important role in the diagnosis of noroviruses until the introduction of the reverse transcription-polymerase chain reaction procedure in the 1990's. In recent years, real time reverse transcription-polymerase chain reaction methodology has emerged as a potentially important diagnostic procedure. The recent introduction of commercial enzyme immunoassay kits has further broadened the range of techniques available to the diagnostic laboratory for detection of noroviruses. In addition, the technique of nucleic acid sequence-based amplification shows promise. This review examines the main features of current diagnostic methods for norovirus identification: electron microscopy, reverse transcription-polymerase chain reaction, real time reverse transcription-polymerase chain reaction, nucleic acid sequence-based amplification and enzyme immunoassay detection using a commercial kit.